## Algorithm

Problem Name: 904. Fruit Into Baskets

You are visiting a farm that has a single row of fruit trees arranged from left to right. The trees are represented by an integer array `fruits` where `fruits[i]` is the type of fruit the `ith` tree produces.

You want to collect as much fruit as possible. However, the owner has some strict rules that you must follow:

• You only have two baskets, and each basket can only hold a single type of fruit. There is no limit on the amount of fruit each basket can hold.
• Starting from any tree of your choice, you must pick exactly one fruit from every tree (including the start tree) while moving to the right. The picked fruits must fit in one of your baskets.
• Once you reach a tree with fruit that cannot fit in your baskets, you must stop.

Given the integer array `fruits`, return the maximum number of fruits you can pick.

Example 1:

```Input: fruits = [1,2,1]
Output: 3
Explanation: We can pick from all 3 trees.
```

Example 2:

```Input: fruits = [0,1,2,2]
Output: 3
Explanation: We can pick from trees [1,2,2].
If we had started at the first tree, we would only pick from trees [0,1].
```

Example 3:

```Input: fruits = [1,2,3,2,2]
Output: 4
Explanation: We can pick from trees [2,3,2,2].
If we had started at the first tree, we would only pick from trees [1,2].
```

Constraints:

• `1 <= fruits.length <= 105`
• `0 <= fruits[i] < fruits.length`

## Code Examples

### #1 Code Example with C Programming

```Code - C Programming```

``````
int totalFruit(int* tree, int treeSize){
int i, j, f, l, m = 0;

int cnt[40001] = { 0 };
int k = 2;

for (i = 0, j = 0; j  <  treeSize; j ++) {
f = tree[j];
if (cnt[f] == 0) k --;  // reached a new type of fruit tree
cnt[f] ++;

if (k == -1) {          // reached the 3rd type of fruit tree
l = j - i;
if (m  <  l) m = l;
while (k == -1) {   // push out one type of fruit tree from head
f = tree[i ++];
cnt[f] --;
if (cnt[f] == 0) k = 0;
}
}
}

l = j - i;
if (m  <  l) m = l;

return m;
}
``````
Copy The Code &

Input

cmd
fruits = [1,2,1]

Output

cmd
3

### #2 Code Example with C++ Programming

```Code - C++ Programming```

``````
class Solution {
public:
int totalFruit(vector<int>& tree) {
int i = 0, j = 0, count = 0;
unordered_map < int, int>m;
int res = 0;
while (j  <  tree.size()) {
if (m[tree[j]] == 0) {
++count;
}
++m[tree[j++]];
while (count > 2) {
if (--m[tree[i++]] == 0) {
--count;
}
}
res = max(res, j - i);
}
return res;
}
};
``````
Copy The Code &

Input

cmd
fruits = [1,2,1]

Output

cmd
3

### #3 Code Example with Java Programming

```Code - Java Programming```

``````
class Solution {
public int totalFruit(int[] fruits) {
Map map = new HashMap<>();
int startIdx = 0;
int endIdx = 0;
int n = fruits.length;
int maxPickedCount = 0;
while (endIdx  <  n) {
map.put(fruits[endIdx], map.getOrDefault(fruits[endIdx++], 0) + 1);
while (startIdx < endIdx && map.size() > 2) {
map.put(fruits[startIdx], map.get(fruits[startIdx]) - 1);
if (map.get(fruits[startIdx]) == 0) {
map.remove(fruits[startIdx]);
}
startIdx++;
}
maxPickedCount = Math.max(maxPickedCount, endIdx - startIdx);
}
return maxPickedCount;
}
}
``````
Copy The Code &

Input

cmd
fruits = [0,1,2,2]

Output

cmd
3

### #4 Code Example with Javascript Programming

```Code - Javascript Programming```

``````
const totalFruit = function (fruits) {
let n = fruits.length
let i = 0, j = 0
const map = new Map()
let res = 0
for(;j  <  n; j++) {
const e = fruits[j]
if(!map.has(e)) map.set(e, 1)
else map.set(e, map.get(e) + 1)

while(map.size > 2 && i < n) {
const tmp = fruits[i++]
map.set(tmp, map.get(tmp) - 1)
if(map.get(tmp) === 0) {
map.delete(tmp)
}
}
res = Math.max(res, j - i + 1>
}

return res
}
``````
Copy The Code &

Input

cmd
fruits = [0,1,2,2]

Output

cmd
3

### #5 Code Example with Python Programming

```Code - Python Programming```

``````
class Solution:
def totalFruit(self, tree: List[int]) -> int:
res = i = 0
last = collections.defaultdict(int)
for j, val in enumerate(tree):
if len(last) == 2 and val not in last:
pre = min(last.values())
i = pre + 1
last.pop(tree[pre])
last[val] = j
res = max(res, j - i + 1)
return res
``````
Copy The Code &

Input

cmd
fruits = [1,2,3,2,2]

Output

cmd
4

### #6 Code Example with C# Programming

```Code - C# Programming```

``````
using System;

namespace LeetCode
{
{
public int TotalFruit(int[] tree)
{
var b1 = -1;
var b1Size = 0;
var b2 = -1;
var b2Size = 0;
var max = 0;

foreach (var treeType in tree)
{
if (b2 == -1)
{
b2 = treeType;
b2Size = 1;
}
else if (b2 == treeType)
{
b2Size++;
}
else if (b1 == treeType)
{
b1 = b2;
b1Size += b2Size;
b2 = treeType;
b2Size = 1;
}
else
{
b1 = b2;
b1Size = b2Size;
b2 = treeType;
b2Size = 1;
}
max = Math.Max(max, b1Size + b2Size);
}
return max;
}
}
}
``````
Copy The Code &

Input

cmd
fruits = [1,2,3,2,2]

Output

cmd
4